A standard belt press used for joining and repairing wide flat belts has a plurality of upper and a plurality of lower traverses respectively having lower and upper traverse faces and upper and lower press platens carried on and between the traverses and having respective upper and lower platen faces respectively confronting the lower and upper traverse faces. Upright tie rods have their upper ends secured in the upper traverse and their lower ends in the lower traverse and can be tightened to move the two platens into a starting position.
A belt to be pressed is engaged between the platens. At least one bend-compensating element having a pair of nonparallel upper and lower surfaces is engaged between one of the platen faces and the confronting traverse faces. A hydraulic actuator is normally braced between the bend-compensating element and one the respective press and platen faces. This actuator can be expanded to move the respective platen toward the other platen.
In order to achieve a smooth finish when vulcanizing a belt, the press platens are longitudinally throughgoing, that is they are of one piece and extend all the way through the press. Heating elements such as described in commonly owned patent application Ser. No. 329,571 filed Dec. 10, 1981 by C. Fudickar (now U.S. Pat. No. 4,426,573) are imbedded in the press platens, which are formed as thick plates. In addition it is standard to integrate the actuators in the thick press platens, and further to build in the various pressure sensors, temperature sensors, and so on that the process requires.
Thus a platen press is normally only available in certain standard sizes, determined by the sizes of the platens available. Even when the platens are formed as separate pieces that each extend longitudinally through several frames, construction is complex and inefficient.